The present invention relates to a laundry washing machine.
More in particular, the present invention relates to a front-loading home laundry washing machine, to which the following description refers purely by way of example without this implying any loss of generality.
As is known, a front-loading home laundry washing machine generally comprises: a substantially parallelepiped-shaped outer boxlike casing structured for resting on the floor; a substantially horizontally-oriented and approximately cylindrical washing tub which is usually suspended in floating manner inside the casing, with the front mouth directly facing a laundry loading/unloading through opening realized in the front wall of the casing; a substantially cylindrical, cup-shaped rotatable drum structured for housing the laundry to be washed, and which is fitted inside the washing tub with the concavity facing the laundry loading/unloading opening, and is supported by the washing tub in axially rotatable manner so as to be able to freely rotate inside the washing tub about its substantially horizontally-oriented, longitudinal axis; a substantially cylindrical, elastically-deformable bellows which watertight connects the front mouth of the washing tub to the laundry loading/unloading opening formed in the front wall of the casing; a porthole door which is hinged to the front wall of the casing to rotate to and from a closing position in which the door closes the laundry loading/unloading opening in the front wall of the casing for watertight sealing the washing tub; and an electrically-powered motor assembly which is structured for driving into rotation the rotatable drum about its longitudinal axis inside the washing tub.
This type of laundry washing machine furthermore comprises: a detergent dispenser which is located inside the boxlike casing, immediately above the washing tub, and is structured for selectively feeding into the washing tub, according to the washing cycle manually-selected by the user, a given amount of detergent, softener and/or other washing agent suitably mixed with fresh water arriving from the water mains; a fresh-water supply circuit which is structured for selectively drawing fresh water from the water mains according to the washing cycle manually-selected by the user, and channelling said fresh water to the detergent dispenser or directly to the washing tub; and finally an appliance control panel which is generally located on the front wall of the casing, above the laundry loading/unloading opening, and is structured for allowing the user to manually select the desired washing-cycle.
In addition to the above, high-end front-loading laundry washing machines may optionally have an internal water softening device which is located along the fresh-water supply circuit, and is structured to selectively reduce the hardness degree of the tap water channelled towards the detergent dispenser and the washing tub. The use of softened water during the washing cycle, in fact, significantly improves cleaning performances.
More in detail, the water softening device is generally internally provided with a given amount of ion-exchange resins which are capable of restraining the calcium and magnesium ions (Ca++ and Mg++) dissolved in the water flowing through the same water softening device, so as to reduce the hardness degree of the tap water directed towards the detergent dispenser and the washing tub.
In addition to the above, since water softening capabilities of the ion-exchange resins are used to quickly drop off after a limited number of washing cycles, this high-end laundry washing machines are generally provided with an internal salt reservoir which is used to selectively produce some brine (i.e. salt water) which, in turn, is periodically channeled into the water softening device to regenerate the ion-exchange resins located therein. Salt water, in fact, is able to remove from the ion-exchange resins the calcium and magnesium ions previously combined/fixed to said resins.
European patent application No. 1085118 discloses a front-loading home laundry washing machine wherein the salt to be used in the regeneration process of the ion-exchange resins is stowed into a salt compartment located on the back of the detergent drawer of the detergent dispenser.
Unluckily integration of the salt reservoir on the back of the detergent drawer has several drawbacks. First of all, during manual extraction and insertion of the detergent drawer inside the drawer housing, the brine contained into the salt compartment may accidentally come out of the detergent drawer and trickle into the basin-shaped bottom portion of the drawer housing that usually collects the mixture of fresh water and detergent, softener or other washing agent flushed down from the detergent compartments of the detergent drawer, with all problems concerned.
The basin-shaped bottom portion of the drawer housing, in fact, directly communicates with the inside of the washing tub, therefore the brine is allowed to freely flow into the washing tub and cause the quick rusting up of all metal parts of the revolving drum, of the electric heater located on the bottom of the washing tub, and of the drain pump and circulation pump of the laundry washing machine.
Furthermore the arrangement of the salt compartment on the back of the detergent drawer leads to a very complicated structure of the detergent dispenser with the consequent significant increase in the detergent dispenser overall production cost.